Evan G., Jeff K.

Summary:
We measured the transfer functions of the OMC DCPD anti-aliasing (AA) module paths of ch13-16 for chassis S1102788. We measure this because the filter board was modified for these channels (LHO aLOG 28010). This is similar to the measurement Kiwamu made in LHO aLOG 21123. The OMC DCPD AA channels are 13 and 14 for DCPD A and B, respectively. The OMC PI AA channels are 15 and 16. We find that the notch behaviour of channel 13 matches what Kiwamu found in LHO aLOG 21123, but the notch of channel 14 is distorted (broken?). Channels 15 and 16 do not have the same notch behaviour (as to be expected for the PI paths, matching LHO aLOG 28085). These differences--compared to the calibration model reference AA filter--are below 1% in magnitude and less than 1 degree in phase below 7 kHz. While the calibration group is unaffected by the broken channel 14, noise from 65 kHz will be aliased down into the detection band. We should consider fixing this.

Details:
The setup for the measurements is shown in the first attachment, and the reference measurement (to remove the gain of the single ended to differential box) is shown in attachment 2. Each transfer function measurement is normalized by the reference measurement transfer function.

Data is saved in /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O2/H1/Measurements/OMCAAChassis

Analysis script is saved as /ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O2/H1/Measurements/OMCAAChassis/process_aachassis_data_20160818.m

Plots are shown in the third attachment. Of particular note is to compare the new measurements to the AA filter model. Channel 14 (OMC DCPD B) now has a different behaviour near the notch. The difference is below 1% in magnitude and 1 degree in phase below 7 kHz, and does not force a revision in the calibration model reference AA filter.

I have updated the Beckhoff SDF system to the latest channel lists. I'll automate this process soon, here is the process I followed (using ecatc1plc1 as an example)

It is assumed that the /opt/rtcds/userapps/release/ecat area is up to date with its req files (which may be in DOS format)

First get the latest autoBurt.req into the ECAT target area:

cd /opt/rtcds/lho/h1/target/h1ecatc1/h1ecatc1plc1epics

cp autoBurt.req archive/autoBurt.req.18aug2016

cp /opt/rtcds/userapps/release/ecat/h1ecatc1/H1ECATC1_PLC1.req autoBurt.req

dos2unix autoBurt.req

Now get this autoBurt into the Beckhoff-SDF target area and use it to generate the new monitor.req file

cd /opt/rtcds/lho/h1/target/h1sysecatc1plc1sdf/h1sysecatc1plc1sdfepics

cp autoBurt.req archive/autoBurt.req.18aug2016

cp ../../h1ecatc1/h1ecatc1plc1epics/autoBurt.req .

cd burt

cp monitor.req archive/monitor.req.18aug2016

grep "^H" ../autoBurt.req | sort > monitor.req

Now restart the SDF target on h1build (as user controls)

h1sysecatc1plc1sdfstartup

If channels have been added, open the SDF MEDM screen and view the 'CHANS NOT INIT' table. Press the global 'MON' button (which selects all channels to ACCEPT and MON) and 'CONFIRM'. Now all new channels are being monitored, commissioners can decide if any should be taken out of this list.

Finally check the snap file changes into SVN.

This week I installed the ISS Outer Loop chassis into H1-PSL-R1, and hooked most of its cables up.  The two AA cables for PDs 5-8 are not hooked up to an AA Chassis yet, and will be hooked up once the original servo is removed from the AA Chassis (The intention is to re-use one of the original ISS Outer loop servo's cables.)  With the PSL down, I was unable to do any system testing.  I have not disconnected any cables from the original servo, so it is still fully functional.  I made an medm screen in UserApps/psl/h1/medm/H1PSL_ISS_OL.adl  All of the new servo's functionality seems to be working.

The TCS system had a bad channel that I traced back to the AA Chassis, S1301168.  It turns out that 2 of the input buffers (U2 on channels 11 and 12) were bad.  I replaced them, and now everything works fine.  In the e-traveller, it seems that these chips have been replaced once before in February, 2015.  We should keep an eye on them.

The broken hose was replaced.  An attached picture shows the burst end of the hose and the fitting that
goes over that end.  The two other attached pictures shows the hose, end on.

    The turbine flow sensor for head 4 was replaced.  Whilst there was no problem with this sensor per
se, its output was somewhat noisier than the three other sensors.  Replacing it now seemed like a prudent
thing to do.  A visual inspection of the flow sensor showed what might be a small build up of material
around the turbine.  If true that would in part explain the noisy signal from this sensor.

    The bulge in the crystal chiller return leg hose section in the chiller room was removed.

    The resonator optics of the high power oscillator were inspected for dust and water marks.  The 4f
lenses for heads 3 and 4 were drag wiped.  The lens in front of the reverse direction power monitoring
photodiode was drag wiped clean.  The fibre bundle ends are being given more time to dry out.




JeffB / Peter

G. Mendell, S. Karki, D. Tuyenbayev

Attached are plots showing the calibration factors (kappa_tst, kappa_pu, kappa_A, kappa_C and f_c)  for ER9 generated from Spectral Line Monitor (SLM)  data, analyzed using Matlab code from Sudarshan Karki and EPICS values from Darkhan Tuyenbayev.

The plots show the calibration factors from

1152010820 == Jul 08 2016 11:00:03 UTC

to

1152097220 == Jul 09 2016 11:00:03 UTC

For example, note the behavior of kappa_C and f_c after 18 hrs in the bottom row of the first attached plot.

A full set of plots can be found by going here,

https://ldas-jobs.ligo-wa.caltech.edu/~gmendell/pcalmon_with_plots/daily-pcalmonNavigation.html

and clicking on July 9 2016 in the calendar in the left frame, and then any of the links to the plots in the middle frame. (To compare with O1, click on Dec. 26, 2015 and then on the links to the plots.)

This morning I restarted h1psliss with the revised re-use of the ISS-ADC channels for the new ISS PD5-8 fast and slow signals. This required a DAQ restart. We took this opportunity to revise the H1EDCU_DUST.ini file and added Jonathan's new daqd diagnostics EPICS channels to H1EDCU_DAQ.ini.

• PSL recovery work
• Opportunistic maintenance work in otherwise sensitive areas
• TCSY work completed
• Tours through the LVEA: US Subcommitee on Research and Tech; Corey's family.

Reconnected flow meter to exhaust of CP4 for measurements toward CP3 manual overfill work-around.
 
Installation caused a quick spike in exhaust pressure >3psi. 

(signal name includes CP3 since the device will eventually migrate to CP3 exhaust - CP4 is temporarily being used to collect data to simulate CP3)

   Jim B., Jeff B.  (WP #6096)

   Jim Batch added the temperature and relative humidity dust monitor channels to EPICs. These channels can now be trended. 

   The dust monitor default alarm level were changed from a Clean-10000 profile to a Clean-100 profile. The dust monitors will now come up with the stricter alarm levels. The alarm levels can easily be adjusted later as circumstances require.    

  

   Took the opportunity, while the PSL was down to Flow test and Zero Count the dust monitors in the PSL enclosure. Both are dust monitors are functioning correctly.   

[Alastair, Jason, Ben, Vern, Dave]

Thanks to everyone for their help getting this work done.  The Y-arm TCS laser is now running full power, and the table is fully aligned.  The in-loop photodiode is also now working again.  Details below.

Tuesday we discovered the laser on the table (SN 20306-20419D) had previously been paired with the driver that went with the spare laser ( 20816D-20510).  The laser had been outputing 40W at the time.  When the Hanford team had swapped in the 'spare' driver they actually were putting in the one that matched up with the laser (SN 20419D-20306) and the power went down to 16W.  First thing we did on Tuesday was to add irises to the table to define the optical axis after the laser.  We added blocks to the table to define laser position We then swapped in the spare laser (20510-20816D) and aligned to the blocking, and we found the power outputs were ~14W with its mating driver, and ~40W with the driver SN20419D-20306.

Checks on as much of the electronics as we could test showed no problems (RF distribution system, controller voltages, power etc).

Wednesday we decided the fastest way to diagnose the drivers was to swap them in to the working X arm table.  Driver SN 20419D-20306 gave a power output of 58W.  Driver  20816D-20510 gave 42W.  Swapping back to the original X arm laser (SN 20706-21015D) and driver combo gave 60W so at this point we left the X-table in its previous working condition.  Conclusion was that driver SN 20816D-20510 has now given output of ~40W on three separate lasers and appears to have some issue.

Moving back to the Y-table, two issues were noticed.  Firstly there was very minor discoloration on one pin of the power cable for the laser.  Ben also said that the pin looked badly seated and did some corrective work on this (we should check with him if he thinks this needs further work).  Secondly the power meter height was adjusted to make sure the aligment to the laser gave the largest apeture possible - this could with a little misalignment oclude part of the beam.

We repeated measurement of spare laser SN20510-20816D with driver 20419D-20306 getting 49W output.  We then completed the cycle of tests by putting in laser 20306-20419D with its matching driver 20419D-20306 and getting 58.6W output.  It's not clear what fixed the problems - the power cable seems a likely candidate but behavior of the laser still doesn't seem totally consistent with this (if one half of the driver was getting no current we would expect ~25W output).  We also might want to test driver  SN 20816D-20510 to check whether the power connector (which looked okay when visibly inspected) might be a cause for its performance drop.

After the laser swaps the final laser configuration was aligned to the blocking on the table and then to the optical axis with some minor tweaking of the actuators on the first mirror on the table.  The laser was aligned through the whole table.  At the mask we aligned by maximizing transmitted power, then using the FLIR camera on remote desktop (yes this works now - thanks Dave Barker) we tweaked the alignment to make the beam symmetrical after the mask.  We then aligned to the irises at the output of the table which define the optical axis into the vacuum system.  We changed the alignment onto the power meter that gives the power output to the CP because the head was too close to a focus.  We checked the calibration of the power output to the CP and this was confirmed accurate.  Finally we aligned to the two photodiodes on the table.  Inloop was not giving an output but we swapped cables with outofloop and were able to get a signal to align to.

The problems with the in-loop photodiode were traced to being a bad ADC board which has now been swapped for the spare (thanks Ben & Jason for tracking this down).

The Y-table will have the output to the vacuum system unblocked so the system is ready to go.  The laser will be left keyed off, with the rotation stage set to minimum power.  When the system is needed it just needs keyed on at the rack in the LVEA, and then power increased at the rotation stage.

Every hour helps - exploiting the water leak recovery

Gerardo, Chandra

Adjusted potentiometer on PT-140A pirani gauge to bring it back on scale. CCW 4 turns. Closed FRS 6061.

NOTE other gauges that were adjusted a few months ago for calibration:  https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=27726

Per WP# 6072 -- 

Activity: PNNL will be coordinating an OTDR test of the fiber pair that feeds the observatory's data connection to make sure that signal strength is appropriate for upgrading to 10Gb/s up from 1Gb/s. Wireless, phones, and internal wired networks at the observatory will be unaffected. Internet access will be interrupted during this work.


Work started at 08:00 PT, completed at approximately 09:10 PT.

If I receive the OTDR data (as viewed from PNNL - ISB2 end), I will attach it to this post.

Terra, Sheila

Tonight we had trouble engaging the ASC again.

• We still have trouble turning up the gain in DHARD, and didn't get a chance to look at this tonight. We did try reverting the ETMX notches but that doesn't solve the problem. 
• We also had trouble with our MICH error point being wrong, which might have been related to TCS being off durring maintence.  Now that TCS has been on for several hours the MICH loop seems to be working OK. 
• We had to restore OMC QPD offsets that weren't in SDF before today's boots.  We are now back in DC readout. 
• Once we reached DC readout we manually tried the CARM gain redistribution that we had commented out of the ANALOG_CARM state yesterday, and we did not see glitches reappear in the MCL drive.  We left this uncommented in the guardian, so we can try this in the morning.
• Jenne reset the soft offsets for our new alignment, and we also got rid of the POP A yaw offset.

Losing optical gain in POP X

We rang up what we think is a PR3 bounce mode when engaging the ASC the same way as last night.  We found that we could avoid ringing this mode up by keeping the PRC2 gain low (digital gains of -500).  Right before the OMC damage/vent, the POP X path was reworked and the optical gain seemed suspiciously low. 

Tonight we found that the optical gain has decreased even more.  Terra changed the demod phase by dithering PR3 pit (500 counts to M3) and rotated the phase positive 65 degrees, (Q1, Q2, Q3, Q4 from 55, 53, 54, 51 to 120, 118, 119, 116 ) to maximize the signal in I (minimize the Q signal).  The 2 attached figures show Terra's before and after OLG measurements (excitation gain of 50), both with Jenne's gain of -5000, showing a 10dB increase in optical gain which is about what we expected based on the dither amplitude change. 

After optimizing the phase, we did not see the 28 Hz mode get rung up, but this seems to come and go because we also didn't see it yesterday.  We quickly tried moving L2 on the POP X path, while watching the amplitude of the PR3 dither line in the POP X signal.  We moved the lens about 4 inches closer to POP X and about 3 inches further away, and didn't find any location that had more signal for PR3 so we replaced it as we found it. 

We are going to leave the IFO locked in DC readout 2 Watts with the request set to down so that it will not try to relock. The noise is bad as expected. 

PEM power supplies in the CER mezzanine were swapped out for Kepco model JQE supplies. This model is a 1/4 rack version, and allows for four power supplies to be mounted on one shelf. This is to make room for the ±24V power supplies that will be used to power Beckhoff/Baffle PD Amplifier/ Spool X/Y camera ect. All PEM instrumentation microphones, magnotometers, ect. were powered down from around 10:30 am to 1:00 pm. All power is now restored.

After I and Evan relocated POP-X and POP-L2, Jenne increased the ASC gain of POP-X by a factor of 250 for PIT and 500 for YAW (alog 28666) just to get back to the old UGF, which sounded crazy to me as I didn't expect much change in Gouy phase.

Just to see if my assumption was wrong and we got super unlucky, I calculated the Gouy phase of the POPAIR path, and it seems like there shouldn't be much change.

In the first attachment, left column is the current configuration, right is the old one. Bottom is the entire POP path from ITM to the ISCT1, and top is the zoomed-in view from HAM1 to ISCT1.

POP-L2 was placed far enough from the waist originally. This lens was moved farther from POP-L1 by 4 inches later, which should have increased the Gouy phase, but it's only 9 degrees. The beam diameter is 2mm now instead of 4mm but that should be OK. These don't explain the crazy decrease of the optical gain.

Funny thing is that the POP-X spectrum itself looks almost the same before and after the relocation (second attachment), so I'm kind of dubious that the optical gain is lost.

It's not totally impossible, but very unlikely, that the Gouy phase was not great to start with, e.g. 81 degrees for the DOF we want to see, and after the change it became 90 degrees.

Executive summary: 

In regard to narrow lines, the (nearly) full O1 H1 data set is little changed from what was reported for the first week's data: a pervasive 16-Hz comb persists throughout the CW search band (below 2000 Hz), accompanied by a much weaker and more sporadic 8-Hz comb; there remain several distinct 1-Hz and nearly-1-Hz combs below 140 Hz, along with other sporadic combs. The 1459.5 hours of 30-minute FScan SFTs used here span from September 18 to the morning of January 3. The improved statistics make weaker and finer structures more visible than in the 1st week's data. As a result, many new singlet lines have been tagged, and it has become apparent that some previously marked singlets actually belong to newly spotted comb structures. The improved statistics also make it more apparent that the originally spotted combs span a broader bandwidth than marked before 

Details: 

Using 1459.5 hours of FScan-generated, Hann-windowed, 30-minute SFTs, I have gone through the first 2000 Hz of the DARM displacement spectrum (CW search band) to identify lines that could contaminate CW searches. This study is very similar to prior studies of ER7 data, ER8 data and the first week of O1 data, but for completeness, I will repeat below some earlier findings.

Some sample displacement amplitude spectra are attached directly below, but more extensive sets of spectra are attached in a zipped file. As usual, the spectra look worse than they really are because single-bin lines (0.5 mHz wide) appear disproportionately wide in the graphics

A flat-file line list is attached with the same alphabetic coding as in the figures.

Findings:

 A 16-Hz comb pervades the entire 0-2000 Hz band (and well beyond, based on daily FScans)
 A typically much weaker and sporadic 8-Hz comb (odd harmonics) is also pervasive (all harmonics are labeled in figures, even when not visible)
 A 1-Hz comb with a 0.5-Hz offset is visible from 10.5 Hz to 133.5 Hz (previously was visible from 15.5 to 78.5 Hz)
 A 1-Hz comb with zero offset is visible from 16.0 Hz to 102.0 Hz (previously was visible from 20.0 to 68.0 Hz)
 A 99.9989-Hz comb is visible to its 11th harmonic (was previously visible to its 8th harmonic)
 The 60-Hz power mains comb is visible to its 9th harmonic (was previously visible to its 6th harmonic)
 There is a sporadic comb-on-comb with 0.088425-Hz fine spacing that appears with limited spans in three places near harmonics of 77, 154 and 231 Hz (ambiguity in precise fundamental frequency)
 There is a doublet 31.4127 and 31.4149 Hz comb visible to their 2nd harmonics (previously marked as only a 31.4149-Hz comb)
 There are three near-1-Hz combs not previous appreciated:

 0.99999-Hz comb from 19.2500 to 50.2497 Hz
 0.99816-Hz comb from 30.9430 to 60.8878 Hz
 0.9992-Hz comb from 30.9738 to 48.9594 Hz

 There is a doublet comb with spacings of 2.07412 and 2.07423 Hz, visible from their 9th to 32th harmonics (18.7-66.4 Hz) 
 There is a hint of another doublet comb with spacings of 99.9735 and 99.9784 Hz, but they are marked as singlets for now


Line label codes in figures:

b - Bounce mode (quad suspension)
r - Roll mode (quad suspension)
Q - Quad violin mode and harmonics
B - Beam splitter violin mode and harmonics
C - Calibration lines
M - Power mains (60 HZ)
s - 16-Hz comb
e - 8-Hz comb (odd harmonics)
O - 1-Hz comb (0.5-Hz offset)
o - weaker 1-Hz and near-1-Hz combs (various offsets, including zero)
H - 99.9989-Hz comb
J - 31.4127 and 31.4149-Hz combs
K - 0.088425-Hz comb
t - 2.07412 and 2.07423 combs
x - single line (not all singlets in the vicinity of quad violin modes are marked, given the upconversion)

Figure 1 - 0-2000 Hz 
Figure 2 - 20-50 Hz sub-band (shows complexity of combs below ~70 Hz)
Figure 3 - 50-100 Hz sub-band (shows continuation of strongest 1-Hz comb with offset of 0.5 Hz)
Figure 4 - 1300-1400 Hz sub-band (shows how clean the noise floor is away from 8-Hz, 16-Hz lines at high frequencies

Attachments:
* Zip file with miscellaneous sub-band spectra (with line labels)
* Flat-file list of lines marked on figures